import java.util.*;

public class dowhile {

   public static void main(String[] pars) {
      int n;
      int x;
      int sum;
      int i;

      Scanner keyboard = new Scanner(System.in);

      // A while-loop for adding n numbers
      System.out.print("Enter n:");
      n = keyboard.nextInt();
      sum = 0;
      i = 1;
      while (i<=n) {
         System.out.print("Enter value:");
         x = keyboard.nextInt();
         sum = sum + x;
         i = i + 1;
      }

      System.out.println("Sum is:" + sum);


      // A supposedly equivalent loop (what is wrong?)
      System.out.print("Enter n:");
      n = keyboard.nextInt();
      sum = 0;
      i = 1;
      do {
         System.out.print("Enter value:");
         x = keyboard.nextInt();
         sum = sum + x;
         i = i + 1;
      } while (i<=n);

      System.out.println("Sum is:" + sum);

      // One ugly way to fix it
      System.out.print("Enter n:");
      n = keyboard.nextInt();
      sum = 0;
      if (n > 0) {
         i = 1;
         do {
            System.out.print("Enter value:");
            x = keyboard.nextInt();
            sum = sum + x;
            i = i + 1;
         } while (i<=n);
      }

      System.out.println("Sum is:" + sum);

      // An even uglier way to fix it
      System.out.print("Enter n:");
      n = keyboard.nextInt();
      sum = 0;
      i = 1;
      do {
         if (n <= 0)     // or if (i>n) break;
            break;
         System.out.print("Enter value:");
         x = keyboard.nextInt();
         sum = sum + x;
         i = i + 1;
      } while (i<=n);

      System.out.println("Sum is:" + sum);
   }
}